The present invention relates generally to hydrogen cooled generators and more particularly to an automated seal oil by-pass system for hydrogen cooled generators.
Hydrogen (H2) gas provides an effective cooling medium in turbine generators because hydrogen's low density and high heat transfer coefficient provide an economical way to increase power density and maintain high efficiency. Conventionally, as shown in FIG. 1, a shaft sealing system 104 between stationary and rotating components isolates the H2 gas in the generator casing 101. Within shaft sealing system 104, high-pressure seal oil enters a set of seal rings and passes radially between the seals and the shaft. The seal oil, at a pressure higher than generator casing 101 H2 pressure, provides a safe and effective seal between the H2 gas and the atmosphere.
Current seal oil systems employ a manual valve arrangement for operator-initiated by-pass of the seal oil in parallel with a float trap 107.